Ornette Coleman is a soft-spoken man, with the gentle, earnest voice of an associate professor at a state college. You might never guess that he has shaken up jazz and set off unending debates about the nature of musical freedom; that he has been denounced as an ignoramus and, more and more often, hailed as a genius.

There was a time when Ornette Coleman's music scared people. His early-1960's albums for Atlantic had combative titles -- ''Change of the Century,'' ''This Is Our Music,'' ''Free Jazz'' -- and promised to break through song forms and eliminate distinctions between foreground and background.